String propelled toy airplane



Dec. 1, 1942.

N. E. WALKER STRING PROPELLED TOY AIRPLANE Sheets-Sheet l Filed Dec. 26, 1940 ATTOR/VEV 1942- N. E. WALKER I 2,303,965

STRING PROPELLED TOY AIRPLANE Filed Dec. 26, 1940 2 Sheets-Sheet 2 FIG. 9

Mull 125E M l F16. 10

Patented Dec. 1, 1942 UNITED STATES PATENT OFFICE STRING PROPELLED TOY AIRPLANE Nevilles E. Walker, Portland, Ores.

Application December 26, 1940, Serial No. 371,622

8 Claims.

My invention relates to toys, and it relates more particularly to toy airplanes of the type adapted to be propelled and controlled by strings. Ordinarily the operator remains stationary, swinging the airplane around in a circle at the ends of strings held either in his hand or by a suitable handle, although at times the operator may move about.

The pfiincipal object of my invention is to en'- able the operator to control the height of a string propelled toy airplane as it flies. To be able to make such an airplane rise or descend at will greatly increases the enjoyment of the sport in itself, and, furthermore, such control is useful in causing the airplane to avoid obstacles that would otherwise damage it. a

A further object of my invention is to provide a handle for manipulating the strings that propel and control the flight of a toy airplane whereby the airplane may be caused to rise or descend by manipulating a lever in the same way that the stick of a large airplane is manipulated to cause the large airplane to rise or descend, as desired. Seemingly, this familiar way of controlling an airplane is most satisfactory, whether the airplane be a large one or a toy.

A further object of my invention is to provide a cheap and practical means for attaching the control strings to a toy airplane in such away. i

that they may be used to vary the height of the airplane as it flies.

Other objects and details of my invention-will be described with reference to the accompanying drawings, in which:

Fig. 1 is a general perspective view of an airplane and control means therefor embodying my invention, the motion thereof being indicated by dotted line views;

Fig. 2 is an enlarged fragmentary bottom view of a portion of the structure shown in Fig. 1;

Fig. 3 is an enlarged sectional view taken on the line 33 in Fig. 1;

Fig. 4 is a view similar to Fig. 2 showing a modification of my invention;

Fig. 5 is an enlarged fragmentary detail view of a portion of the structure shown in Fig. 4;

Fig. 6 is an enlarged sectional view taken on the line 6-6 in Fig. 5;

Fig. '7 is a fragmentary front elevation of the airplane shown in Fig. 1;

Fig. 8 is a fragmentary ture shown in Fig, 7; a

Fig. 9 is a section taken on the line 9-9 in m.

plan view of the struc 10 is a section taken on the line Ill-l0 in Fig. 7; and

Fig. 11 is a view-similar to Fig. 10 of a modification of the wing structure there shown.

A toy airplane l is adapted to be propelled and controlled by strings 2 and 3. Said toy airplane resembles generally ordinary toy airplanes or gliders, but it differs therefrom in several slight, but nonetheless important, .respects. For convenience, I will describe said airplane as I prefer to construct it for flight as shown in Fig. 1, that is, around from right to left in front of the operator. If it is desired to fly the airplanein the opposite direction, it will be understood that certain structural features should be reversed.

When a person swings a toy airplane around in a circle at the end of a string centrifugal force tends to hold the string taut. It will be apparent, then, that the character of the flight of the airplane will be afiected by varying the point of attachment of the string to the airplane. If said point of attachment is ahead of the center of mass of the plane, and the string lies substantially in the plane of the wings, the pull of the string will cause the airplane to yaw toward the operator-an undesirable result since the string then slackens, preventing further immediate control of the airplane. Means for preventing this inward yawing of the airplane are hereinafter described.

0n the other hand, if the airplane is above the operator so that the string slopes downwardly from the airplane, as is shown in Fig. 7, and said string is attached to the airplane ahead of its center of mass, the pull of the string will cause the airplane to nose downward and descend. Or,

if the string be attached to the airplane behind the center of mass, its pull will cause the airplane to nose up and rise. Thus, two strings, one ahead of and the other behind the center of mass, will serve to'control the elevation of the airplane as it flies, pulling on one of said strings causing the airplane to rise and pulling on the other string causing it to descend. It will be understood that a point of attachment ahead of the center of mass means that the point is further advanced along the'line of flight than the center of mass, that is forward thereof and that a point behind or aft of the center of mass is one less far advanced along the line of flightthan ever, to achieve this result it is necessary that the airplane shall roll outwardly, somewhatas shown in Fig. 7, instead of banldng. If the airplane banked the strings would merely cause the right wing 5, either by tilting wing 4 at a steeper angle than wing 5, thus giving wing 4 greater incidence than wing 5, as is indicated in Figs. 9

' and 10, or by giving wing 4 a more camber than wing 5, as is indicated in Fig. 11. I call the lifting power of the wing the lift of the wing, however it is achieved, and I prefer the left wing to have greater lift than the right wing in order that the airplane shall tend to roll outward rather than to bank. It will be understood that to achieve the desired result, the lift of the left wing will have to be considerably greater than that of the right wing since, with the airplane flying in the assumed direction in a circular path, the right wing travels faster than the left wing and so normally has more lift, causing the airplane to bank.

Ordinarily, centrifugal force will hold the airplane away from the operator, keeping the strings taut. However, I have found that it is desirable to set rudder 6 permanently so as to cause the airplane to tend' to yawto the right. I do this for the dual purpose of keeping the strings taut and causing the airplane to roll outwardly due to its dihedral angle. The latter result is brought about by the lift of the left wing due to its dihedral when the airplane is turned to the right so that the left wing is, so to speak, nosing into the wind. As is shown in Fig. 8, rudder 6 causes the airplane to turn toward the right, but the strings will not permit it to go that way, so the airplane skids thru the air with the left wing leading.

I deem this setting of the rudder to be of great importance. If the strings are not to slacken when the forward string is pulled to cause the airplane to descend, there must be a strong tendency for the airplane to roll outwardly, and an excellent way to bring about this outward rolling is merely to set the rudder to cause the airplane to yaw to the right. Furthermore, this means for causing the outward rolling of the airplane facilitates its climbing when the strings are attached to the left wing some distance from the fuselage, as is shown in Fig- 8. When rear string 3 is pulled, causing the tail of the airplane to drop and its nose to rise, the lift of wing 4 due to its dihedral lifts the whole airplane. This result would not be achieved if the rudder were not set to cause wing 4 to nose or point into the wind.

A long handle 'I is convenient for swinging a toy airplane. I prefer to pivotally attach lever 3 thereto. by means of pin 9, and to attach string 2 to one end of said layer and string 3 to the other end thereof. Then, when handle I is held so that the end of said lever to which string 2 is attached is upward, lever 3 functions like the stic of a large airplane in that pulling back on the upper portion thereof will cause the airplane to'rise, while pushing said upper portion forward will cause the airplane to descend. Of

course,.suitable eyes or holes it should be pro vided near the outer end of handle I for guiding strings 2 and 3.

As mentioned, I prefer to attach strings 2 and 3 to left wing 4 some distance from fuselage ll. Inasmuch as said wing will ordinarily be made of thin balsa wood which crushes easily and which has little tensile strength, considerable difficulty is encountered in attaching said strings in a cheap and simple manner. Of course, toy airplanes must be cheaply constructed if they are to be widely sold. I flnd that clip i2 may be fastened to the wing by means of eyelets, and a plurality of holes [3 at opposite sides of the center of mass may be provided therein for attaching strings 2 and 3. By attaching said strings to various holes, the control characteristics desired by the individual operator may be,

achieved. Strings 2 and 3 should be so spaced that 2 will lie along a line passing forward of the center of mass of the airplane, while 3 lies along a line passing aft of said center of mass. It will be understood that the point of attachment of said strings will depend to a certain extent upon the position of rudder 6.

An alternative means for fastening strings 2 and 3 to wing 4 is a scissors fastener l4 comprising two pivotally secured members defining rearwardly extending legs l5 provided with barbs 16 adapted to dig into the wood of the wing, and forwardly extending legs l1, one on each member and having eyes Hi to which strings 2 and 3 may be attached. A rubber band I9 may a barbs and resetting them, the resiliency of the rubber band permitting this action.

I claim:

1. A toy airplane adapted to be swung at the end of two flexible members, said airplane comprising an elongated body and two elongated wing-elements secured to said body at their inner endsand extending laterally from said body, said wing elements being of substantial width and extending forward and aft of the longitudinal center of mass of said airplane, plural attaching means for said flexible members secured to the under surface of one of said wing elements defining plural points of attachment for said flexible rlembers, forward and aft, respectively,

of said cmterline, whereby a pull on the flexiblemember secured forward of said centerline will cause the airplane to yaw in one direction and a pull on the other flexible member will cause the airplane to yaw in the opposite direction.

2. A toy airplane adapted to be swung at the end of two flexible members, said airplane comprising an elongated body and two elongated of said centerline, whereby a pull on the flexible member secured forward of said centerline will cause the airplane to yaw in one direction and a pull on the other flexible member will cause the airplane to yaw in the opposite direction, means for varying the point of attachment of said flexible means with respect to said centerline.

3. A toy airplane adapted to be swung at the end of two flexible members, said airplane comprising an elongated body and two elongated wing elements secured to said body at their inner ends and extending laterally from said body,

said wing elements being of substantial width and extending forward and aft of the longitudinal center of mass of said airplane, plural attaching means for said flexible members secured to the under surface of one of said wing elements defining pluralpoints of attachment for said flexible members, forward and aft, respectively, of said centerline, whereby a pull on the flexible member secured forward of said centerline will cause the airplane to yaw in one direction and a pull on the other flexible member will cause the airplane to yaw in the opposite direction, adjustable means for varying the point of attachment of said flexible means with respect to said centerline.

4. A toy airplane adapted to be swung at the end of two flexible members, said airplane comprising an elongated body and two elongated wing elements secured to said body at their inner ends and extending laterally from said body, said wing elements having a substantial dihedral angle, said wing elements being of substantial width and extending forward and aft of the longitudinal center of mass of said airplane, plural attaching means for said flexible members secured to the under surface of one of said wing elements defining plural points of attachmentfor said flexible members, forward and aft, respectively, of said centerline, whereby a pull on the flexible member secured forward of said centerline will cause the airplane to yaw in one direction and a pull on the other flexible member will cause the airplane to yaw in the opposite direction, rudder means on said body set at an oblique angle to said body to cause said airplane to yaw in said latter direction.

5. A toy airplane adapted to be swung at the. end of two flexible members, said airplane comprising an elongated body and two elongated wing elements secured to said body at their inner ends and extending laterally from said body, said wing elements being of substantial width and extending forward and aft of the longitudinal center of mass of said airplane, attaching means for said flexible members secured to the under surface of one of said wing elements defining points of attachment for said flexible members, forward and aft, respectively, of said centerline will cause the airplane to yaw in one direction and a pull on the other flexible member will cause the airplane to yaw in the opposite direction, said wing elements having a substantial camber tending to cause said airplane to tend to climb in flight, the wing element to which said attaching means is secured having greater lift than has the other wing element.

6. A toy airplane adapted to be e at the end of two flexible members, said lane comprising an elongated body and two elongated wing elements secured to said body at their inner ends and extending laterally from said body, said wing elements being of substantial width and extending forward and aft of the longitudinal center of mass of said airplane, attaching means for said flexible members secured to the under surface of one of said wing elements defining points of attachment for said flexible members, forward and aft, respectively, of said centerline, whereby a pull on the flexible member secured forward of said centerline will cause the airplane to yaw in one direction and a pull on the other flexible member will cause the airplane to yaw in the opposite direction, said wing elements having a substantial camber tending to cause said airplane to tend to climb in flight, the wing element to which said attaching means is secured having greater camber than has the other wing element.

7. A toy airplane adapted to be swung at the end of two flexible members, said airplane comprising an elongated body and two elongated wing elements secured to said body at their inner ends and extending laterally from said body, said wing said centerline will cause the airplane to yaw in one direction and a pull on the other flexible member will cause the airplane to yaw in the opposite direction, said wing elements having a substantial camber tending to cause said airplane to tend to climb in flight, the wing element to which said attaching means is secured having greater incidence than has the other wing element.

8. A toy airplane adapted to be swung at the end of two flexible members, said airplane comprising an elongated body and two elongated wing elements secured to said body at their inner ends and extending laterally from said body, said wing elements having a substantial dihedral angle, said wing elements being of substantial width and extending forward and. aft of the longitudinal center of mass of said airplane, attaching means for said flexible members secured to the under surface of one of said wing elements defining points of attachment for said flexible members, forward and aft, respectively, of said centerline, whereby a pull on the flexible member secured forward of said centerline will cause the airplane to yaw in one direction and a pull on the other flexible member will cause the airplane to yaw in the opposite direction, means for varying the point of attachment of said flexible means with respect to said centerline, rudder means on said set at an oblique angle to said body to cause. said airplane to yaw in said latter direction, said wing elements having a substantial camber tending to cause said airplane to tend to climb in flight, the wing element to which said attaching means is secured having greater liftthan has the other wing element. 

